So, after some effort, I managed to install some car mods I downloaded from gta4-mods.com . The mods themselves are working perfectly, only problem is that now, car variety has all but disapeared. By car variety I mean the unmodded ones, because when I'm driving through the city, all I see are cars like the one I'm driving (doesn't matter which car I'm driving, they are always like mine) taxi cabs, and 1 or 2 different car types (I.E: I'm driving a Coquette, next to me there are only cabs, police cars, and sometimes Presidentials or some other brand). When the game does show other cars different than mine, they come in batches, like clones, for example, 5 or 6 cavalcades in a row and so on. It's really annoying the hell outta me, you can guess why. If anyone knows a fix, or the cause of this problem, please, do tell me.

I've done a light research about this and can't find any decent awnser, but, seeing as I'm an amateur regarding mods and etcetera, this may be a common glitch with an easy (or not) fix. Also, I don't know if this is the right location to report this kind of problem, so if it isn't, please forgive me.

This is known as the taxi-bug, it happens when installing custom cars. The traffic will be full of taxi's, police cars and sometimes the car you're driving.

There are some taxibug fixes out there that claim to solve the problem but in my experience they only fix the problem partially, the amount of taxis is reduced but there'll still be more taxis then usual. I'd suggest first trying to set traffic density to 20 (or lower) before trying out any taxibug fixes.

If that doesn't do anything just google taxibug fix gta 4 and you'll find several, like trafficcontrolsystem or trafficload. Don't use more then 1 at a time, some of those fixes do some damage to performance so it's best to try 1 at a time.